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23

The camera usually keeps the aperture open as wide as possible while framing the shot. It is only closed to the setting you dialed in when the picture is being taken. This allows for a brighter viewfinder and more of the auto focus points to be used. As described in the manual of your camera on page 114, there's a dedicated button to stop down the aperture ...


21

You are correct that the term "macro" means large scale (e.g. macroeconomics), however its use in photography is relative to microphotography, that is imaging using microscopes. The tradition definition of a macro lens is one that can achieve a 1:1 magnification, which means the image projected onto the recording medium is life size. So for a common APS-C ...


21

Sure. There's something called a light field camera, or plenoptic camera. It captures a much lower resolution than a normal camera, but it also captures additional information that allows it to be refocused after the fact. And to a very limited degree, dual-pixel RAW in the Canon 5D Mark IV allows refocusing after the fact, but not by very much. That ...


21

While this is a rare instance of need, it's a shame there isn't a photographic equivalent of the red field with white diagonal stripe "diver down" flag, or the more internationally-recognized blue-and-white "Alpha" flag. Perhaps she could fashion her own "photographer in action" sign, with a combination of symbols for instant ...


20

what shall i do please to have high magnification inside pulp canals with high magnification more than 25x Buy a suitable microscope. No DSLR lens will provide the level of magnification you need, particularly at a focal distance that makes sense for dentistry. Macro lenses get a lot of their ability to magnify just from being able to focus at very short ...


20

Macro photography is all about the skill of the photographer, lenses, and lighting - in that order. Only after the former have been considered should the differences between two APS-C cameras from the same manufacturer that appear to both use the same sensor be considered as a relatively minor difference. The primary differences between the EOS Rebel T7i/...


18

Technically any software that is capable of stitching regular photos would be capable of stitching macro photos as well. However, to be able to accurately stitch photos they need to be taken with little or no parallax (movement of the camera's optical centre). This is typically achieved by rotating the camera/lens about it's optical centre using a "VR" ...


18

Scootbb has a great answer, but I would suggest that you have some custom shirts, hoodies or jackets made for her with wording on the back. Bonus points for you if you give them to her as a gift. On the back it could say "I am not dead or injured, just taking photos" or any wording you feel is appropriate. This may preferable to carrying a sign. ...


14

"Strobists" are the followers of teachings of David Hobby published in his blog, "The Strobist". Strobism is usually characterized by using small flashes (designed for on-camera use) in manual mode off camera to achieve better lighting than available from ambient lighting. The flashes are often accompanied by portable and/or DIY light modifiers and set-up ...


14

It depends entirely on how the lens was designed, there is no general formula or way of determining the minimum focus distance. Lenses of the same focal length can have completely different minimum focus distances depending on which factors the lens designer chose to optimise.


14

You are just too close to your subject. Cell phone cameras and "Point and Shoot" cameras can take photos from very close distances. DSLR cameras can not. It is actually the lens that determines how close you can shoot. Most general purpose lenses have a minimum focus distance of about 9-12 inches. If you need to focus closer you can buy a specialty "Macro" ...


14

A lens only focuses on one plane. For normal cameras / lenses the plane is parallel to the film/sensor, so only objects at a particular distance from the lens will be in perfect focus, though things some way in front of and behind that plane will be acceptably sharp. smaller aperture settings (bigger f numbers) increase that range, and larger aperture ...


13

You can also use the hugin toolset which includes the align_image_stack and enfuse tools. You may also wish to add the EnfuseGUI to cut down on the typing. Works very well Free & Open Source Multi-platform runs on Mac/Windows/Linux There is a very nice walk through here.


13

The principle of physics behind this behaviour is nothing more than the thin lens formula: 1/o + 1/i = 1/f Where o is the object distance (distance from lens to subject), i is the image distance (distance from lens to sensor), and f is the focal length. For a very large object distance (approaching infinity) the 1/o term drops to zero, hence: 1/i = 1/f i ...


13

Macro and portrait lenses are generally designed to do two different things that require different design characteristics. Macro lenses are designed to focus at very close distances and they typically render a fairly flat field of focus. There are a few very specialized macro lenses that can only focus at the very close focus distances required by macro ...


13

Macro and close-up photography require having the correct lenses. Upgrading the body won't do much good. If you don't already have suitable lenses, the money would be better spent getting one. Before upgrading the body, it would be helpful to first identify what is unsatisfactory about your current setup. Otherwise, you risk getting another camera with ...


13

There is no direct relationship between Telephoto focal lengths and Macro capability. There are some fixed focal length prime lenses that fall into the Telephoto range in terms of focal length and also are capable of close enough focus to be Macro lenses. But a lens doesn't have to be a telephoto lens to have Macro capability and there are many Macro lenses ...


12

A simple lens (like the lens in a pair of glasses) forms an image at a distance of f behind the lens for an object at infinity (where f is the focal length). The same lens will form an image at 2f behind the lens for an object 2f in front of the lens. This will achieve 1:1 magnification, i.e. the definition of macro. Thus any single element lens is a macro ...


12

Flipping a lens around by itself doesn't make it a macro lens. However, since that is the main purpose of flipping a lens, a reverse mount moves the lens farther from the camera than it would be normally, giving it the ability to focus closer. This is the same effect as extension tubes. The reason for flipping the lens instead of just moving it farther ...


12

You are seeing chromatic aberration — a prismatic effect which, as you nicely illustrate, reduces sharpness even in black and white photography. A lens which has greater correction for this is called an apochromatic lens — often something like "APO" in the lens name. Note that in lenses for telescopes and microscopes, you'll often also see achromatic ...


11

There is no direct relationship between Telephoto focal lengths and Macro capability. Macro lenses allow closer focusing than most lenses. By allowing you to get the subject closer to the camera, it allows you to increase the size of the subject in your photo. Macro capability is measured in terms of Maximum Magnification (MM) that is only indirectly ...


11

If, specifically, you want to cover telephoto and macro, and not necessarily general-purpose nearby photography or wide angle shots, then yes, this is no problem, because relatively long focal length macro lenses are a common design. Sony, for example, has a 100mm f/2.8 macro lens. This won't quite give you the reach of a more extreme telephoto lens (...


11

Whenever you're freelensing (holding the lens against the camera, rather than securing mounting it), you do run the danger of getting stuff inside the camera body (including stray light), but as long as you watched out to make sure nothing comes in contact with the lens elements, you probably aren't damaging your lens. The main "issues" (or features, ...


11

The equation assumes a simple single element lens that is bilaterally symmetrical. The camera lens, to mitigate the 7 major aberrations (shortcomings that degrade) is constructed using several individual glass lens elements. Some are positive in power, some with negative power. Some are air-spaced apart and some are cemented together. Because this array ...


10

None of the lenses have macro capabilities - but you can probably get good images of lego-sized objects (maybe with a little cropping). Just try, set up some object similar to what you want to photograph, make sure you have lots of light and the entire object is well lit. Hint: for a static indoor scene low ISO, a tripod, cable release and a window that ...


10

I'm not quite sure why you're so skeptical; it's well-explained and the explanation seems plausible. To respond to your particular points, having read the page: The setup with the stool and glass is used for the photos where the snowflakes are on the glass and backlit. They are on the glass, 2.5-3cm away from the lens. The rings on the front of the lens (...


10

One cheap option is that you buy a reverse lens adapter. Of course, you need to take care so you do not let dust inside your camera or let the lens get scratched. You can also increase the magnification adding a black cardboard tube, for example of 2 inches or 5 cm long. A cheaper option is using a camera cap as an adapter. I recommend that you only use ...


10

I am understanding several issues here. I am going to separate them and you can choose an option. The blurriness. You are actually now using a 105 mm macro lens. Assuming you know how to use it, and you have tested it, for example outside of the mouth of a patient, you know how close you need to be and what "magnification". Then "Blurriness" could mean ...


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